The present invention relates to the control and monitoring of the operation of subsea wells. More particularly, the present invention relates to a distributed system for the control and monitoring of a plurality of wells in a subsea field.
In practice, there are three types of wells to be controlled: production wells, wells that are being maintained (“work-over wells”), and drilling wells. Each is traditionally controlled from a surface platform by dedicated control equipment attached to a riser and a wellhead tree (in the production environment) or a blowout preventer (BOP) (in the drilling or work-over environment). Such dedicated control systems are expensive, heavy, and complex and, a dedicated system for each well is typical. Thus, there is a long-felt need to reduce the number of such control systems and to reduce the complexity of the risers that must be used with them.
In situations in which some wells are producing in an area near where other wells are being drilled or worked over, various types of vessels and control equipment are used. As described above, typically the control systems for the drilling operations are different from those for the production operation, and both are different from the work-over situation. Thus, there is a need to reduce the number and type of control and distribution systems in areas or fields in which production, drilling, and/or work-over operations are occurring in order to overcome some of the foregoing difficulties while providing more advantageous overall results.